Telephone switching apparatus.



F. R. MQBERTY.

TELEPHONE SWITCHING APPARATUS.

APPLICATION FILED T11R27, 190s. RENEWED NOV. 12, 1913.

16 SHEETSSHEET 1.

Inventor:

THE NORRIS PETERS co.. PHDTO LITHO. WASHINGTON, D C

F. R. MQBERTY.

TELEPHONE SWITCHING APPARATUS.

APPLICATION FILED FEB. 27. 1903. RENEWED nov. 12, 1913.

1,126,048. Patented Jan. 26, 1915.

16 SHEETS-SHEET 2.

Inventor:

Attest: GA 0 51 THE NORRIS PETERS CO FHUTO-LITHO WASHINGTON, D. c.

F. R. McBERTY. TELEPHONE SWITCHING APPARATUS. APPLICATION FILED FEB. 27, 1908. RENEWED NOV. 12, 1913. 1,12 ,04 Patented Jan. 26, 1915.

18 SHEETS-SHEET 8.

Attest: I ventor:

THE NORRIS PETERS C0,, PHOTCVLITHOH WASHINGTON. D c

F. R. MoBERTY.

TELEPHONE SWITCHING APPARATUS.

urmoumn FILED EBB. 21, 190B. RENEWED HOV.12, 191a.

Patented Jan. 26, 1915.

16 BHEETS-SHEET 4.

Attest:

F. R. MoBERTY.

TELEPHONE SWITCHING APPARATUS.

v APPLICATION FILED FEB. 27, 1908. RENEWED NOV. 12, 1913. 1,126,048. Patented Jan. 26, 1915.

16 SHEETS-SHEET 6.

HIE NoRRl: PETERS Lil. PHOTCVLITHO WASHINGTON. n. C

Q {Ti Sn tor:

F. R. MoBERTY.

TELEPHONE SWITCHING APPARATUS.

APPLICATION FILED 11213.27, 190a. nnnnwnn NOV. 12, 1913.

1,126,048. Patented Jan. 26, 1915.

16 SHEETS-SHEET 6.

Inventor:

NORRIQ' FEM-2R5 CO IHOYO LITHOY. WASHINLTON by C.

F. R. MGBERTY.

TELEPHONE SWITCHING APPARATUS.

APPLIUATION rum) PEB.27, 190s. RENEWED NOV.12, 191s.

Patented Jan. 26, 1915.

16 BHEETSSHEET 7.

I g uon F. R. MGBERTY. TELEPHONE SWITCHING APPARATUS. APPLICATION FILED FEB.27,1908. RENEWED NOV. 12, 1913,

1 ,1 26 ,048, Patented Jan. 26, 1915.

16 $HEETSSHEET 8.

. Inve tor: QAMA 0. M

THE. NORRIS PE1ER5 C0,. PHOTc-L!THO.. WASHINGTON. D c.

F. R. MEBERTY TELEPHONE SWITCHING APPARATUS. APPLICATION FILED FEB. 21, 1908. RENEWED NOV. 1,126,048.

Patented Jan. 26, 1915.

16 SHEETS-8HBET 9.

Inventor:

W 1 m M Attest INF NORRIS PETERS c0 PHOTO LITHU WAFHINKJVON n c F. R. MUBERTY.

TELEPHONE SWITCHING APPARATUS.

APPLICATION FILED FEB. 27, 1908. RENEWED 110mm, 1913. 1,126,048.

ww 9T 1 m 6 2H R d8 6 %1 n w a P 'm/ems PETERS co PHoro L VTHQ, WASHINL rowv D C.

F. R. McBERTY.

TELEPHONE SWITCHING APPARATUS. APPLICATION FILED FEB 21, mos. RENEWED NOV. 12, 1913. 1,126,048.

THE NORRIS PETERS co.. PHOTG-LITHO.. WASHINGTON, D c.

F. R. MGBERTY.

TELEPHONE SWITCHING APPARATUS.

APPLICATION FILED rBB.27, 190B. RENEWED NOV. 12, 1913.

Inventor: M I? min Attest:

F. R. MoBERTY. TELEPHONE SWITCHING APPARATUS. APPLICATION FILED FEB. 27, 1908. RENEWED NOV. 12, 1913. 1 ,126,048. Patented Jan. 26, 1915.

16 SKBETPBHBET 13.

Attest: I Q lnv 193m vur unmels PETERS Lu PHOTC LITHO WASHINGTON. D C

F. R. MGBERTY.

TELEPHONE swncums APPARATUS.

- APPLICATION FILED FEB. 27, 1908. RENEWED NOV.12, 1913. 1,126,048 Patented Jan. 26, 1915.

16 SHEETS-SHEET 14.

Inventor:

WNW 31:2;

IHF NORRIS PETERS C0,, PHOTO LHHQ. WASHJNC m n r F. R. MGBERTY. TELEPHONE SWITCHING APPARATUS. APPLIGATION FILED $1313.27, 1908 RENEWED NOV.12, 191s Patented Jan. 26, 1915.

16 SHEETS-SHEET l5.

THE NORRIS PETERS ca. PHOTCVLITHO WASHINGTON, D. C.

F. R. MoBERTY.

TELEPHONE SWITGEING APPARATUS.

APPLICATION FILED FEB. 21, 1908. RENEWED NOV. 12, 1913.

Patented Jan. 26, 1915.

16 SHEETS-*BHEET 16.

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HE NORRIS PETERS co PHOTOVLITHO WASH/Ni, raw 1.; v

UNITED STATES PATENT OFFICE.

FRANK R. MGBERTY, OF NEW ROCHELLE, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE SWITCHING APPARATUS.

Specification of Letters Patent.

Patented Jan. 26, 1915.

Application filed February 27, 1908, Serial No. 418,126. Renewed November 12, 1913. Serial No. 800,666.

T 0 all whom it may concern:

Be it known that I, FRANK R. MCBERTY, a citizen of the United States, residing in the town of New Rochelle, in the county of lVestchester and State of New York, have invented a certain new and useful Improve ment in Telephone Switching Apparatus, of which the following is a full, clear, concise, and exact description.

My invention relates to telephonic apparatus designed to be employed in the interconnection for conversation of the telephones of a telephone exchange, and is directed more particularly toward the provision of switching apparatus for use in a system wherein interconnection between the telephones is effected through the agency of electrically actuated devices under the control of an operator at the central office to which the lines of the exchange extend.

My invention has for its principal object the provision of simple and inexpensive switching mechanism whereby interconnection between any two lines of a telephone exchange system may be effected with the greatest possible ease and rapidity, with the minimum of effort on the part of the subscriber desiring connection, and without requiring special apparatus at the subscribers stations.

In the so called automatic telephone systems, as commonly practised, it is the cus tom to provide at the central office of the exchange automatic switches or selectors upon "which the lines terminate, and which are adapted to effect interconnection between "arious lines of the exchange, these automatic switches being controlled in their operation by means of special calling apparatus sometimes referred to as senders or controllers located at each subscribers station and manipulated by the subscriber to cause the auton'iatic switches at the central ofiice to complete the connection he desires. These systems not only necessitate the provision of special, and sometimes highly complicated, apparatus at each substation, which apparatus is usually expensive and also liable to derangement; but they also impose upon the subscriber the necessity of doing the work incident to establishing the connection between his line and the line for which he is calling. In the so called manual systems, on the other hand, no special calling apparatus need be provided at the subscribers station, as these systems involve the employment of an operator at the central office who receives the call from the subscriber, and performs the work necessary to the es tablishment of the connection. But in large systems of this character, a large percentage of the calls for connection must be trunked. that is, each call must be extended by means of a trunk line to a particular one of a number of groups into which the lines of the exchange are divided. The establishment of such a connection, therefore, involves the services of at least two operators,the operator who first answers the subscriber and obtains from him the number of the line with which he desires connection, and the operator who presides over the distant end of the trunk line through which connection is made to the particular group in which the called line is located. The trunking of a connection involves a conversation between the subscribers operator and the trunk operator, in which the trunk operator is apprised of. the number of the line called for, and in turn informs the subscribers operator of the number of the trunk line OYQI which the connection is to be extended. This method of completing connection between the subscribers lines not only necessitates the em ployment of a large force of operators, but is also subject to objection arising from error in repeating the number of the line with which connection is desired, and in designating the number of the trunk line that is to be employed in establishing the connection.

The system in which the apparatus of my invention is particularly adapted to be employed aims to combine the best features of operation of the automatic system and of the manual system, and to eliminate the objectionable features of both. In accordance with the embodiment of this system which I have herein illustrated, and which I shall describe, the substation equipment is of the usual character, and does not involve any special calling apparatus. The subscribers lines extend to a central oflice, where they are terminated in such a manner that a call for connection operates a signal that attracts the attention of the operator. The operator is provided with switching means for putting herself into communication with the calling subscriber and ascertaining his wants; and also with connecting means through which the line of the calling subscriber may be extended to a circuit over which his line, without any further effort on his part, and without requiring the services of another operator, may be brought into connection with the particular line for which he is calling.

The circuit over which connection with the called line is established, is provided with an automatic switch, constructed in accordance with my invention, which has access to connection terminals of the line with which connection is desired, and which is under the control of a calling device adapted to be manipulated by the operator who answers the subscribers call. Upon receiving the call of the calling subscriber the operator sets the calling device with which she is provided, and when she has completed connection with the trunk line extending to the group in which the called line is included, the automatic switch at the other end of the trunk operates under the control of the calling device to select and establish connection with the particular line with which connection is desired. In this way the work which in an automatic system is performed by the subscriber himself, and which requires special calling apparatus at his substation, is, in the system equipped with the switching apparatus of my invention, performed by the operator at the central otfice; while the work of completing connection with a called subscriber-s line located in a particular group and at a point remote from the point where the calling subscriber is answered, which work is in a manual system performed by a trunk operator in response to spoken instruction from the subscribcrs operator, is in the system provided with the apparatus of my invention accomplished by an automatic switch controlled by the operator who answers the subscribers call.

My invention contemplates a number of improved instrumentalities for use in this or other systems. The automatic switching apparatus which I have devised for use in this system is adapted to perform, under the control of the operator who answers the subscribers call, all the work incident to selecting, testing, connecting with, ringing and disconnecting the called line which a trunk operator would perform under the verbal instructions of the answering. operator; and the calling device operated by the answering operator is adapted to be set and controlled by that operator to govern the movement of the automatic switch in performing the various operations referred to above.

Briefly stated, the system in which the embodiment of my invention illustrated and described herein is particularly designed to be employed operates as follows. The act of the calling subscriber in taking his telephone for use displays at a central station switchboard a signal which leads the answering operator to complete connection with the calling line by inserting one of the plugs of a pair of connecting cords into a spring jack associated with said signal. Vhen the operator has learned the number of the line with which the calling subscriber desires connection, she sets her calling de vice to correspond to the number of the desired line, inserts the other plug of the pair of connecting cords into the spring jack of a trunk line extending to the group of lines of which the called line is one, and presses a key which brings the calling device into operative relation with the automatic switch at the other end of the trunk line. As soon as the calling device and automatic switch are brought into operative relation a local source of power associated with the automatic switch is made operative to drive it, and the movement of the switch produces impulses that in turn serve to drive the calling device. The automatic switch has a number of rows of stationary terminals wired to the lines that terminate on the spring jacks in the switchboard, and a number of movable terminals that are caused to pass over the stationary terminals in the movement of the switch, each movable terminal being arranged to pass over a particular row of stationary terminals. lVhile all of the movable terminals are connected with the trunk line, none of them is normally in condition to engage the terminals of the row over which it moves, but the switch is provided with mechanism that acts under the control of the calling device to select a patricular one or group-of the movable terminals, and bring it into position to engage the stationary terminals of its associated row. The particular movable terminal selected depends upon the degree to which the movable terminals-which all move togetherhave been displaced from their normal or resting position when the selecting mechanism operates; so, inasmuch as the automatic switch controls the movement of the calling device so that they both move together, the operator, by setting the calling device to produce, after a predetermined movement. a current change that actuates the selecting mechanism, is able to bring about the operation of the selecting mechanism of the automatic switch at any predetermined point in its movement, and is thus able to select and make active any desired one of the movable terminals. The movement of the automatic switch is stopped by the operation of mechanism associated with the switch and actuated by another current change controlled by the calling device; and, as the extent of movement of the selected movable terminals of the switch at the moment it is stopped determines the particular stationary terminal-and therefore the particular subscribers line-with which the movable terminal of the trunk switch completes connection, the operator, by setting the calling device to produce this other current change after a predetermined movement of the calling device, is able to stop the correspondingly moving automatic switch with its selected movable terminal in engagement with any desired one of the stationary terminals.

When the called line is thus selected a testing relay is brought into action to prevent the trunk line from being extended to the selected line in case the latter is busy, and to transmit a busy signal to the other end of the trunk. If the line is not busy, connection with it is completed and ringing current is applied by means of a circuit which is automatically disconnected when the called subscriber answers the call. The talking circuit of the trunk is at the same time completed at this end, and, as the devices at the other end of the trunk line have operated in the meanwhile to disconnect the calling device and complete the trunk circuit at that point, the calling subscriber and the called subscriber are now brought into communication. During the use of their telephones, both subscribers have control of the usual supervisory signals before the op erator. When they replace their telephones the operator disconnects, and the resultant change of current flow in the circuit causes the return of the automatic switch to its normal position.

In the system in which I have illustrated the switching apparatus of my invention as being employed, the reciprocal control over each other of the calling device and the automatic switch, the control of the called subscribers supervisory signal, the transmission of the busy signal if the line is engaged, and the telephonic communication between the subscribers are all effected over the usual single pair of conductors. The control of the calling device over the automatic switch to cause it to perform its various operations of starting, selecting a particular movable terminal, selecting and connecting with a particular stationary terminal and returning to normal position is effected through the medium of switching apparatus at the automatic switch end of the trunk, which operates at each change of current flow produced by the calling device to shift the control of the calling device from one to'the other of the various operating circuits and mechanisms of the automatic switch.

The foregoing is an outline of the system as a whole in which the switching apparatus of my invention is particularly designed to be employed. In order that a clear understanding of the operation of the switching apparatus of my invention may be had, I

shall fully describe the telephonic system in which I have shown it to be used in the present instance, together with the other devices which cooperate with the switching apparatus in this system; but it will be understood that the switching mechanism toward which the claims of the present application are particularly directed is capable of being advantageously employed in organizations other than the particular one in connection with which it is here illus trated.

I shall describe the switching apparatus of my invention, and the telephone system in which, in the present instance, it is employed, more in detail by reference to the accom panying drawings, wherein Figure l is a diagrammatic representation of the circuit arrangement of one form of telephonic system in which the switching apparatus of my invention may be organized, portions of the automatic switch being illustrated in perspective; Fig. 2 is a plan view of a calling device adapted to cooperate with the switching apparatus of my invention in the system illustrated; Fig. 3, a plan view of the calling device with the cover removed; Fig. 4 a side elevation of the calling device with the outer casing partially broken away; Fig. 5, a vertical cross section on line 55 of Fig. 3; Fig. 6, a perspective of the plate carrying one of the contact levers of the calling device; Fig. 7, a perspective view of another of the plates with its associated switches; Fig. 8, a detail plan View of the controlling magnet of the calling device with its escapement mechanism; Fig. 9, a front elevation of an automatic connector switch embodying my invention, the switch carriage being shown rotated from its normal position in order that the construction and arrangement of the parts may be more clearly seen; Fig. 10, a rear elevation of the automatic switch with its parts in the position shown in Fig. 9; Fig. 11, a side elevation of the switch with its parts as shown in Fig. 9; Fig. 12, a top plan view of the same; Fig. 13, a top plan view with the movable terminals of the switch in their normal position; Fig. 14, a sectional plan view on line l41l of Fig. 9; Fig. 15, a section on line 1515 of Fig. 9; Fig. 16, a perspective view of the switch carriage, or movable element of the switch, carrying the movable terminals with their associated parts; Fig. 17 a perspective view of the other side of the switch carriage; Fig. 18, a detail view of some of the stationary terminals of the switch; Fig. 19, a detail of one of the latches that hold the movable terminals clear of the stationary terminals; Fig. 20, an enlarged detail, partially broken away, of the interrupter segments of the switch; Figs. 21 and 22, enlarged detail views of the tripping and resetting portions of the automatic switch, Fig. 21 showing the relation between the tripping mechanism and the bank of movable terminals prior to the tripping operation, and Fig. 22 illustrating the relations between the parts at the moment of tripping, and also showing in dotted lines the tripped movable terminal as it rides up on the insulation of the terminal block in which the stationary terminals are mounted; Fig. 23, a top plan view of the dish portion of the magnetic clutch that drives the switch; Fig. 24, a front elevation of the clutch, with the disk portion shown in section on line 24l2 l of Fig. 23; Fig. 25, a detail view of the contact plate shown in Fig. 7, with a portion of the escapement wheel of the calling device, to illustrate the relation between the parts when the escapement wheel is in its normal position; and Fig. 2-6, a top view of the interrupter segments.

I shall first describe the automatic switch of my invention, which, under the control of the answering operator, performs the office of a trunk operator in establishing connection with the called line. This switch comprises primarily a number of stationary terminals mounted in a terminal block, a carriage or traveler carrying a number of movable terminals or brushes with means for normally holding the movable terminals or brushes clear of the stationary terminals and for measuring the movement of the carriage, a tripping device for tripping any one of the movable terminals so as to bring it into position to engage the stationary terminals in the corresponding row, a resetting device for restoring the tripped movable terminal to its normal position upon the return of the carriage or traveler, driving mechanism for causing the movement of the carriage, a magnet for controlling the operation of the driving mecha nism, and a frame to which all of the above mentioned parts are secured and by means of which they are supported. I

The supporting frame consists of a base piece 8 to which two uprights s are secured by means of two lugs .9 These uprights are shown broken off at their upper ends in the drawing, as they may be made long enough to support a number of switches S arranged one above the other. Above the switch S the uprights s are braced by means of a cross piece 8 The different parts of the switch are secured to the support in three groups, any one of which may be detached from the support without disturbing the others. One of these groups includes the stationary terminals 8 in their mounting block and one part of the interrupter which measures the movement of the switch carriage. The second group consists of the carriage or traveler carrying the movable terminals 8 the other element of the interrupter, the tripping mechanism, a cam switch associated with the carriage, and one element of the magnetic clutch by means of which the carriage is driven. The third group comprises the power shaft and the other element of the magnetic clutch.

The stationary terminals 8 consist, in the present instance, of metal punchings, which may conveniently be of brass and have the form illustrated in Fig. 18. These punchings are mounted in parallel rows in a ter minal block 3 of hard rubber, or like suitable insulating material. The terminal block 8 is substantially semicylindrical in form, and for convenience in manufacture may be divided into twoor more parts, as shown. The holes in the terminal block in which the stationary terminal punchings s are placed may be formed in any convenient manner, but I prefer to produce them by milling a number of vertical slots in the inner face of the cylinder 8 and a number of horizontal slots in the outer face, the series of slots being milled deep enough to intersect each other and form holes at the points of intersection. In this way, the openings for the terminal punchings are formed more readily than they would be by drilling each hole sepa rately. The slots cut in the surfaces of the terminal block divide each surface into a series of parallel webs arranged transversely on the two surfaces. Inasmuch as the movable terminals that traverse the inner ends of the stationary terminals move across the ends and have a tendency to displace them in a horizontal direction, I cut the slots so that the webs on the inner surface of the terminal block extend vertically, so as to support the ends of the terminals against horizontal displacement; while the horizontal arrangement of the webs on the outer surface of the terminal block supports the corresponding ends of the terminals against displacement in a vertical direction by the vertically extending wires or cables connected with the outer ends of the terminals. In the present in stance, I have illustrated the switch as be ing provided with sixteen hundred and twenty stationary terminals arranged in thirty parallel horizontal rows having fiftyfour terminals in each row; and I have shown the terminal cylinder 8 as being divided horizontally into two parts, each containing half of the terminals.

The terminal punchings s are preferably formed with shoulders 3 near their forward ends, as shown in Fig. 18, these shoulders being adapted to lie against the front walls of the horizontal slots in the terminal block to limit the forward movement of the terminals. The sides of the shoulders are also provided with arc-shaped depressions, so that insulating rods 8 may be thrust 

